Experimental study of thermal comfort in a vehicle cabin during the summer season

Abstract

Thermal comfort evaluation for vehicle occupants is very complicated due to the transient nature and non-uniformity of the vehicle interior. The thermal sensation of an automotive occupant is affected by the surrounding environment. More than this, the actual standard is proposing three evaluation indexes and was developed for steady state and controlled conditions and some of the indexes are not adapted for this complex environment. In this article the three standardized indexes values are compared in term of thermal comfort, in a vehicle passenger in summer season. The results are showing that the mean values of PMV/PPD model calculated in a single point with Comfort Sense equipment are far from the TSV mean values which was collected in questionnaires, while the teq index which was calculated with an advanced thermal manikin are closer to the TSV comfort votes. This may be explained by the fact that the TSV and teq consider the sensation for each body part at the local level. For a correct evaluation of the thermal comfort in non-uniform and transient environments like in the vehicles, is not enough to measure in a single point and the results to be considered in all the ambiance. The main conclusion is that the PMV/PPD indexes are not very well adapted to the vehicle environment.